Cylinder lock-key-combination, a key therefor and a method of producing the key from a key blank

ABSTRACT

A cylinder lock-key-combination includes a lock cylinder, a cylinder housing (2) and a cylinder plug (3) provided with a key slot (3a) and a row of tumblers (5). The tumblers (5) and associated key (4) present mutually adapted engaging and receiving members which function to forcibly guide movement of the tumblers in two opposite axial directions as the key is inserted into the lock. For instance, the pin tumblers (5) include a circular flange (5a) and a side surface of the key (4) includes a groove (4b) which extends along the length of the key and whose width varies so as to accommodate the flanges of the rotatable or twistable tumblers. Alternatively, the tumblers are provided with a groove or a waisted portion and the key is provided on a side surface thereof with a rail which engages in the groove or waisted portion. In addition, the tumblers (5) may be provided with waisted portions (5b) to enable the tumblers to function as latching pins in coaction with a side-bar, or to form bottom tumblers for coaction with corresponding spring-activated top tumblers, or to function as locking pins in direct engagement with bores provided in the lock housing. The invention also relates to a key for forcibly guiding the pin tumblers, and also to a method of manufacturing such a key from a key blank.

FIELD OF INVENTION

The present invention relates to a cylinder lock-key-combination, andmore specifically to a cylinder lock-key-combination of the kind definedin the preamble of claims.

The invention also relates to a key for such a combination, and also toa method of producing such a key from a key blank.

BACKGROUND ART

SE,B, 422,491 (GKN-Stenman) and U.S. Pat. No. 4,393,673 (Widen) describea combination of this kind in which the key, in addition to a web part,has a side part which includes a coded surface having code parts orshoulders for engagement with an edge part of one end of the respectivepin tumblers and with transition parts which extend in the direction ofthe long axis of the key between mutually adjacent code shoulders. Thecode shoulders and transition parts of the side part of the key includeparts of surfaces which are described by a point or by a line or curveprovided with an end point which rotate with said point for said endpoint at a given distance from a point on an axis which extendsgenerally parallel with the axes of the pin tumblers, said axes movingcontinuously or discontinuously in a plane that extends through the pinaxes or in a plane which is generally parallel therewith.

The pin tumblers may coact with spring-activated top tumblers or maythemselves be activated and provided with waisted parts for coactionwith outwardly projecting shoulders on a side-bar.

The side-bar is spring-biased outwardly from the cylinder, intoengagement with a recess in the lock housing, this recess beingconfigured to urge the side-bar into the cylinder plug as it rotates,subsequent to having inserted the correct key into an operative positionin the plug. The side-bar includes a number of lugs having roundedengagement surfaces which coact with waisted parts of the side-bar. Inmanufacture, the coded surfaces and the intermediate transition surfacesmust be produced very accurately, and consequently the cylinder locktaught by this prior publication is comparatively expensive to produce.

U.S. Pat. No. 5,067,335 and SE,B, 455,801 (Widen) describe another typeof lock which is provided with a side-bar and the pin tumblers of whichare guided forcibly in different directions of rotation and have a formwhich makes the lock expensive to produce.

U.S. Pat. No. 3,264,852 (Gysin) teaches a cylinder lock with which thereis used a key which is provided on the side surfaces thereof withgrooves which, when the key is inserted to an operative position in theplug, coact with tumblers that have outwardly projecting pins forengagement in respective grooves. The tumblers of this lock do not coactwith a side-bar. Moreover, the pins on the tumblers are subjected to arelatively high degree of wear, which is liable to jeopardize thefunction of the cylinder lock after long-time use.

Another example of the standpoint of techniques is found in DE,C,575,828 (Albert Brun in Paris).

OBJECTS OF THE INVENTION

One object of the present invention is to provide a cylinderlock-key-combination which can be manufactured simply and the mutuallycoacting, movable parts of which will be subjected only to a smalldegree of friction, causing only slight wear on said movable parts andachieving continued reliable function of the combination over a longperiod of use.

Another object of the invention is to provide a combination of theaforesaid kind which will function smoothly and effectively even inharsh environments, for instance when the lock is exposed to moistureand/or cold.

A further object of the invention is to provide a cylinder lock of smalldimensions which will nevertheless provide an extraordinarily largenumber of possible combinations, therewith making it difficult to forcethe lock.

DISCLOSURE OF THE INVENTION

These and other objects of the invention are fulfilled with an inventivecylinder lock-key-combination of the aforesaid kind which is mainlycharacterized by the features set forth in the characterizing clause ofclaims.

The mutually coacting engaging and receiving members ensure that thetumblers are moved forcibly in an axial direction into their respectivecoded positions. At the same time, the tumblers are able to rotate ortwist freely in the cylinder plug, meaning that mutually coactingengagement surfaces vary and that these mutually coacting members willonly be subjected to a small degree of wear.

The friction between mutually coacting components is relatively small,particularly in those cases when the tumblers are not acted upon bysprings. This increases the length of useful life of the lock.

The forcibly guided movement of the tumblers means that the tumblersneed not be spring-activated. However, the lock may be provided withsprings which, for instance, engage the tops of the tumblers so as toensure that the tumblers will move to desired positions in the axialdirections of said tumblers upon withdrawal of the key.

A principle embodiment of the invention is characterized by thecharacterizing features set forth in claims. In this case, the groovemay be straight and extend parallel with those parts of the key whichextend in the key-insertion direction and which normally define the codepositions of the key and intermediate, angled transition parts ofgreater width.

This double engagement of the tumbler flanges, on both the top and thebottom surfaces thereof, results in more accurate positioning of thetumblers in respective code positions. The intermediate, angled andwider transition parts of the groove will offer only slight resistanceto key movement as the key is inserted into and withdrawn from the plug.

However, the inventive concept also includes the possibility of definingone or more code positions in the angled transition parts of the key.Movement of the pin tumblers at right angles to the key-insertiondirection is extremely precise, insofar as the pin tumblers take adefinable position in the movement plane of the pins in each keyposition. The provision of a code position in an angled transition partrenders it difficult to determine the code positions of the key.

The tip of the key may have a widening end-region adjacent the groove.This ensures that when the key is moved to an operative position in theplug, the groove will capture all of the pin flanges, irrespective oftheir positions. To this end, the end of the key may conveniently beprovided with a V-shaped recess or notch which is delimited by acorresponding V-shaped shoulder part which converges with the groove atthe apex of the V.

According to one advantageous embodiment of the combination, the plug ofthe cylinder lock is provided with a side-bar accommodating recess, inwhich case the tumblers can be designated latching pins. The side-bar ismovable in a plane which is perpendicular or generally perpendicular tothe plane of the latching pins.

In this case, the cylinder housing also includes a groove or a recesswhich accommodates the side-bar in its locking position, and theside-bar includes a member, for instance a tongue, which in its releasedposition coacts with a corresponding member, for instance, a groove or awaisted portion on the tumblers in the tumbler row, so that the side-baris able to leave the recess in the cylinder housing as the plug isturned.

In order to ensure reliable function, it is preferred that the side-baris activated by one or more driving pins which coact with the sidesurface of the key and which are guided for movement in the plug atright angles to the plane of the key slot and which function to pressthe side-bar out to its locking position as the key is withdrawn fromits operative position with the side-bar in its release position.

Thus, the side-bar is also guided forcibly in the aforedescribed manner,thereby ensuring that the side-bar will function reliably. By guidingthe driving pins in the cylinder plug, it is ensured that no jammingwill occur as the side-bar moves.

It is conceivable to use only one driving pin in certain cases, althoughit is normally preferred to provide one driving pin at which end of theside-bar.

The driving pins may optionally be enclosed by springs which facilitateand assist movement of the side-bar to its locking position.

In order to ensure that the driving pins will function as intended, theends of the pins distal from the side-bar will preferably engage in acorresponding recess or notch in the key, when the key is fullyinserted. Those ends of the driving pins which enter the recess arepreferably tapered conically to form a pointed tip, which facilitatesthe purpose of the driving pins in urging the side-bar into its lockingposition as the key is withdrawn from its operative position. In otherwords, the tips of the driving pins are moved up out of the recesses asthe key is withdrawn, therewith moving the side-bar forcibly into itslocking position.

In this connection, in order to ensure that the driving pins and theside-bar will function smoothly and effectively, the rectilinear, normalcode positions of the key groove are extended along a distance whichexceeds the radius of the driving pins, as in accordance with onepreferred embodiment of the invention. The pin tumblers will therewithremain in their code positions during the initial phase of withdrawingthe key, during which the driving pins, as they leave their respectiveapertures or recesses, will urge the side-bar in a direction generallyat right angles to the key withdrawal direction.

Normally, these extended parts of the code positions will correspondroughly to the diameter of the driving pins, therewith ensuring that thedesired movement sequence is carried out correctly.

The driving pin aperture or apertures in the key is/are preferablyformed in conjunction with manufacturing the key blank. Thus, theapertures, or recesses, may be formed in direct conjunction withclipping the key blank from a metal plate.

However, instead of being provided with apertures or recesses of thiskind, the key blank may be provided with depressions or hollows whosedepths correspond to or exceed the penetration depth of the member, e.g.the tongue on the side-bar, in corresponding members, e.g. the waistedpart of respective tumblers. This will ensure that the side-barcorrectly leaves its release position and is forcibly guided to itslocking position as the key is withdrawn. The key cannot be turnedunless these apertures, recesses or depressions are correctlypositioned. The apertures, recesses or depressions may be differentlyplaced, e.g. for the classification of different series of cylinderlocks.

The plug space can be utilized to the best effect when the other side ofthe key is also grooved for coaction with a further row of pin tumblersand a side-bar in the cylinder plug. The cylinder may then be madeshorter.

It will be understood that the number of code combinations for the lockconcerned can be increased exponentially in this way. It is alsopossible to allow the edge surfaces of the key between the two groovedside surfaces thereof to coact with pin tumblers of a more or lessconventional kind, thereby further increasing the combinationpossibilities of the lock.

In the case of one particular application of the invention, the key slotprovided in the plug can accommodate two different keys, each forcoaction with respective pin tumblers accommodated in each plug half,each of these pins, in turn, coacting with a respective side-bar in theaforedescribed manner.

In such cases, a lock of this kind can be used when two persons areauthorized to open a lock in unison, each of these persons having one ofthe keys in his/her charge. In this case, it is impossible to open thelock unless both persons are present with their respective keys at oneand the same time.

In the case of an alternative embodiment, the flanged tumblers formbottom tumblers which coact with preferably spring-activated toptumblers, optionally through the agency of one or more intermediatetumblers. The flanges will then suitably be spaced from the ends ofrespective tumblers and will have a part of smaller diameter on theirtop and bottom sides.

According to another alternative, the pins may function as locking pinsfor direct engagement in the cylinder housing, i.e. without coactingwith an top tumbler. In this case, the flanges are conveniently spacedfrom both ends of respective tumblers.

Another principle embodiment of the invention has the characteristicfeatures set forth in claim 12. The pin tumblers of this embodiment arealso accommodated in the cylinder lock for rotation about theirlongitudinal axes. In this case, the axial length of the waisted portionwill preferably exceed the width of the rail. When the tumblers aremoved to their locking positions as the key is withdrawn, it is ensuredthat one part of the waisted portion of respective tumblers will belocated in the region in which the forward part of the key rail willmove as the key is again inserted into the key slot in the core in orderto reopen the lock.

It is preferred in practice to delimit the waisted portion of respectivetumblers by conical transition parts. This facilitates engagement of thetumblers as the key is inserted and movement of said tumblers as theypass the angled parts of the code groove.

Both of the principle embodiments of the invention may have thecharacteristic features set forth in claim 6, therewith renderingforcing of the lock difficult, and --when so-called intermediatetumblers are used--the lock can function as a system lock whichincorporates a master-key and a standard-key function.

Forcing of the lock is made still more difficult when the inventivecombination has the characteristic features set forth in claim 7.

The difference between the spring force of all counteracting springswill therewith correspond suitably to approximately the spring forceexerted by a standard tumbler spring in a cylinder lock.

In this arrangement, the stronger spring will compress the weaker springto a minimum length. In the locked position, the stronger spring willmove adjacent top or bottom tumblers and the intermediate tumblers andthe key-actuable tumbler to a position in which the cylinder plug cannotbe turned. A double locking function is therewith achieved in this case.This makes the lock cylinder particularly difficult to force.

For instance, if the key-actuable tumbler is moved as far as possibleagainst the action of the stronger spring when attempting to force thelock, the central tumbler will take a locking position while, at thesame time, the bottom or top tumblers and the intermediate tumblersacted upon by the weaker spring will be moved to a locking position.This makes it particular difficult to force the lock.

The best function is obtained when the stronger and weaker springs arepositioned in the manner defined in claim 10.

The ends of the central, key-actuable tumblers will preferably bechamfered so as to enable the pins to readily enter corresponding topand bottom holes in the lock cylinder. The ends of the top tumblers,when present, will also be chamfered.

It is preferred in both of the aforesaid principal embodiments that thekey slot is positioned asymmetrically in the plug, such that the tumbleraxes will lie essentially in the centre plane of the plug. In thisembodiment, the dividing plane between the central tumbler and thecoacting top and bottom tumblers and the intermediate tumblers willobtain the most advantageous position.

It is also possible within the scope of the invention to displace thetumblers laterally, so that their axes lie in a plane on one side of asymmetry plane through the plug. However, in this case, the dividingplane between the central tumbler and the top and bottom tumblers willtake a sloping position in relation to the tumbler axes, which mayimpair the correct function of the cylinder lock. For instance, when thecentral tumbler and the top and the bottom tumblers are provided with anoblique surface for correct coaction, certain limitations are causedwith regard to the ability of the central tumbler to rotate about itslong axis in the cylinder plug. As defined in claim 13, obliquelydrilled tumbler holes may also be provided. In this case, it isnecessary to turn the key through 360° before it can be removed from thelock, therewith enhancing lock security.

The invention also relates to different types of keys for respectivecombinations of the aforesaid kind, these keys being characterizedmainly by the characteristic features set forth in claims 21 and 22.

According to another aspect, the invention also relates to a method ofmanufacturing a combination key from a key blank, this method beingcharacterized mainly by the characteristic features set forth in claim23.

The invention will now be described in more detail with reference to anumber of exemplifying embodiments thereof and also with reference tothe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an inventive combination, comprising alock cylinder and an associated key.

FIG. 2 is a sectional view of the lock cylinder shown in FIG. 1, takenon the line II--II.

FIG. 3 is a sectional view of the lock cylinder shown in FIG. 2, takenon the line III--III.

FIG. 4 is a sectional view of the key shown in FIG. 1, taken on the lineIV--IV.

FIG. 5 is a sectional view of the lock cylinder shown in FIGS. 1-3subsequent to having inserted the key and turned the key through 90°.

FIG. 6 is a sectional view corresponding to FIG. 5, subsequent tocommencing withdrawal of the key from its operative position.

FIG. 7 is a sectional view corresponding to FIG. 2 with the key insertedand subsequent to commencing turning of the plug.

FIG. 8 is a perspective view of a pin tumbler.

FIG. 9 is a sectional view corresponding to FIG. 3 and illustrates amodified embodiment in which the plug includes two rows of pin tumblers,wherein the tumblers of each row are intended to coact with a respectiveside-bar, and in which the key slot is intended to accommodate two keys.

FIG. 10 is a side view of a key blank for the manufacture of a key of acombination constructed in accordance with the invention.

FIG. 11 illustrates the cutting of a groove in a key blank according toFIG. 10, such as to provide the blank with a side code.

FIG. 12 illustrates the configuration of the groove in the vicinity ofthe tip of the key.

FIG. 13 is a sectional view corresponding to the view of FIG. 3 andillustrates a modified embodiment in which the cylinder plug is providedwith double rows of pin tumblers and associated side-bars and also toptumblers.

FIG. 14 is a cross-sectional view of a modified embodiment, in which theflanged tumblers in said tumbler rows are positioned more centrally inthe plug and the key slot and function as top tumblers which coact withbottom tumblers.

FIG. 15 is a side view of one such flanged tumbler.

FIG. 16 is a side view of another tumbler configuration.

FIG. 17 is a view corresponding to FIG. 11 and illustrates the key bladeupon completion of a milling operation.

FIG. 18 is a sectional view taken on the line XVIII--XVIII in FIG. 17.

FIG. 19 is a sectional view taken on the line XIX--XIX in FIG. 17.

FIG. 20 is a perspective view of one embodiment of an inventivecombination comprising a lock cylinder and an associated key.

FIG. 21 is a front view of the lock cylinder shown in FIG. 20.

FIG. 22 is a sectional view taken on the line XXII--XXII in FIG. 21.

FIG. 23 is a perspective view of a key belonging to an alternativeprincipal embodiment of an inventive combination.

FIG. 24 is a sectional view taken on the line XXIV--XXIV in FIG. 23.

FIG. 25 is a front view of a lock cylinder belonging to a combinationaccording to the alternative principal embodiment.

FIG. 26 is a sectional view taken through the lock cylinder on the lineXXVI--XXVI in FIG. 25.

FIG. 27 is a sectional view of an inventive lock cylinder forming partof a system lock in accordance with the first principal alternative.

FIG. 28 is a front view of the lock cylinder shown in FIG. 27.

FIG. 29 is a sectional view of a further modification of a lock cylinderaccording to the first principal alternative.

FIG. 30 is a front view of the embodiment shown in FIG. 29.

FIG. 31 is a side view of a key which is provided with rail meansaccording to the alternative principal embodiment, this key being amodified version of the key illustrated in FIG. 23.

FIG. 32 is a sectional view of the key shown in FIG. 31, taken on theline XXXII--XXXII.

FIG. 33 is a sectional view of the key shown in FIG. 31, taken on theline XXXIII--XXXIII.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates a cylinder lock-key-combination which comprises of alock cylinder 2 and a key 4. the lock cylinder 2 accommodates a plug 3provided with a key slot 3a.

As shown in FIGS. 2 and 3, the plug 3 accommodates a row of pin tumblers5 which coacts with a side-bar 6 and whose axes lie in a plane whichextends parallel with the plane of the key slot 3a and spaced from saidplane. The pin tumblers 5 are movable in said plane and can be twistedor turned about their geometric axes.

The pin tumblers 5 are provided at their respective bottom ends with aflange 5a which is received in a groove 4f in the side surface 4c of thekey 4. The configuration of the groove will be described in more detailherebelow.

The plug 3 also includes an aperture 3c which accommodates the side-bar6. The side-bar 6 coacts with the pin tumblers 5 and is movable in saidaperture in a plane that extends at right angles to the plane of the pintumblers, although it may define an angle relative to this plane.

The side-bar has a narrowing forward part 6a which is accommodated in acorrespondingly shaped aperture or recess 2a in the lock cylinder 2. Onelong side of the side-bar includes a tongue 6b which is intended toengage a waisted part 5b of respective pin tumblers 5. FIG. 3 shows theside-bar 6 in its locking position, in which the tongue 6b does notengage a waisted part 5b, therewith preventing the side-bar 6 fromleaving its locking position. The pin tumbler 5 will not take a positionin which the side-bar 6 is able to move to its release position untilthe correct key 4 has been inserted in its operative position in theslot.

The key 4 has an top edge surface 4b which may be optionally providedwith a code (not shown) in a conventional manner, for coaction with anadditional pin tumbler (not shown) in the plug.

The key 4 includes a key grip 4a and a shoulder 4d that forms an topdefining surface of a side part 4c in which the aforesaid groove 4f isformed for coaction with the flanges 5a on respective pin tumblers 5.

The width of the groove 4f varies and the groove includes a number ofstraight code parts 4e and intermediate angled transition parts 4g whosewidths are greater than the code parts 4e.

The groove widens outwardly at the tip of the key, as indicated at 4h,so as to ensure that the flanges 5a of the pin tumblers 5 will beengaged by the groove.

As the key 4 is inserted, the groove 4f will engage both the top and thebottom sides of the flanges 5a on the pin tumblers 5 and therefore forcethe tumblers to move to their respective code positions.

The plug 3 is provided with bores 3e in the region of the ends of theside-bar 6, for accommodating driving pins 7 having heads 7a whichengage respective end-parts of the side-bar 6. The ends of the drivingpins 7 which face towards the key slot 3a narrow conically and areintended to be received in recesses or notches 4i in the end regions ofthe blade part of the key 4, as the side-bar moves to its releaseposition.

The driving pins 7 are also intended to move the side-bar 6 forcibly toits locking position. FIG. 5 is a sectional view of a lock cylinderaccording to FIGS. 2 and 3, with the key inserted and turned through90°. In this operational state of the lock, the side-bar 6 is in itsrelease position and the conical ends 7b of the driving pins 7 arelocated in the recesses or notches 4i in the key 4.

FIG. 6 is a view which corresponds to FIG. 5 and which illustratesinitial withdrawal of the key from its operative position. Thus, the key4 has been withdrawn through a distance which slightly exceeds theradius of the driving pin 7. The tips 7b of the driving pins havetherewith left the notches 4i in the key while moving at right anglesthereto and urging the side-bar 6 outwards to its locking position. Thecylinder housing 2 includes an elongated recess 2a for accommodating theside-bar 6 in its locking position.

The driving pins 7 thus ensure that the side-bar will be forcibly guidedto its locking position as the key is withdrawn from the key slot 3a. Inorder to ensure that the pin tumblers 5 will not move from their codepositions upon initial withdrawn of the key, the straight code positions4e of the groove 4f are extended so that all pin tumblers 5 will remainin their respective code positions until the side-bar has been pressedoutwardly from its locking position by the driving pins 7.

The positions of respective waisted portions 5b of the pin tumblers 5and the position of the tongue 6b on the side-bar 6 may be varied.

FIG. 7 shows the key 4 inserted to an operative position in the lock,wherein the pin tumblers 5 automatically take their coded positions inwhich the tongue 6b of the side-bar 6 is able to enter the waistedportion 5b. As the plug 3 is turned by the key, the side-bar 6 ispressed inwardly to the release position shown in FIG. 7, in whichposition the plug 3 can be turned.

FIG. 8 shows the pin tumbler 5, its flanges 5a and its waisted portion5b. The illustrated pin tumbler also presents a number of "false"waisted portions 5c of smaller depth than the waisted portion 5b, torender forcing of the lock difficult.

FIG. 9 illustrates an embodiment in which two different keys must beinserted in the divided key slot 4a' in order to open the lock. Each ofthe keys (not shown) coacts with a pin tumbler/pin tumbler arrangementaccording to the earlier Figures. Alternatively, a single key in whichthe key blade is divided into two parts may be used.

FIG. 14 illustrates the manner in which the invention is applied in analternative cylinder lock which lacks a side-bar. Instead, the lockinghousing 2 includes a row of tumblers channels 2d which accommodate toptumblers 13 that are activated by springs 14.

In addition to the key slot 3a, the plug 3 also includes a row of bores3d which lie in register with the bores 2d in the lock housing 2 whenthe plug 3 is in the position shown in FIG. 14 and the key is withdrawn,therewith latching the plug. In this case, the tumbler 5 provided withflange 5a functions as a bottom tumbler and includes a part 5b which isreceived in the bore 3d of the plug. Located between the tumbler part 5band the tumbler flange 5a is a narrower part 5c, and a correspondingnarrow part 5e is also provided beneath the flange 5a. The flange 5a isthus located at a distance from the end of the tumbler and has a part ofsmaller diameter on its top and bottom sides.

One or more intermediate tumblers may be provided between the bottomtumbler 5 and the top tumbler 13 in a conventional manner, so as toenable the lock to be expanded to form a system lock.

FIG. 15 is a side view of the flanged bottom tumbler 5 used in the FIG.14 embodiment.

FIG. 16 illustrates another possible configuration of the flangedtumbler 5, which in this case is intended to function as a latching pin,i.e. without coacting with bottom tumblers. Instead, the top or thebottom part of the flanged tumbler will engage directly with acorresponding bore in the cylinder plug. The flanged tumbler may bespring-activated in the case of this embodiment.

FIG. 10 illustrates a key blank from which a key for use with the lockillustrated in FIGS. 1-8 and in FIG. 14 can be produced. The key blankmay be clipped from metal plate and has a key grip and a key blade whichis provided with the two notches or recesses 4i for coaction with thedriving pins. The front end of the key blank has a V-shaped recess ornotch 4h which forms a widened end-part of the groove provided in theside surface of the key blade.

FIG. 11 illustrates the manufacture of a key from the key blank shown inFIG. 10, by milling a groove 4f of the relevant kind with the aid of amilling tool 10 driven by a drive means 11. The thickness of the millingtool 10 corresponds to the width of the groove 4f in the region of thestraight code parts 4e. As the milling tool and/or the key blank moverelative to one another, transition parts 4g are formed between the codeparts 4e, these transition parts 4g having a greater width than the codeparts 4e. The widened end region of the groove 4f is illustrated in moredetail in FIG. 12, where the V-shaped parts of the groove are referenced4k.

FIG. 17 illustrates a part of the key 4 corresponding to FIG. 11 uponcompletion of the code groove 4f in the side part 4c. The sectionalviews shown in FIGS. 18 and 19 illustrate the code groove 4g moreclearly, partly with respect to its straight code parts 4f (FIG. 18) andpartly with respect to the sloping transition parts 4g (FIG. 19).

It will also be seen from FIGS. 17-19 that the straight parts 4f of thecode groove are slightly wider than the tumbler flanges 5a with whichthey are intended to coact, whereas the sloping parts 4g of the codegrooves have a greater width. As will be seen from FIG. 18, the codegroove is concave in the junctions between the straight parts 4f and thesloping parts 4g.

FIG. 13 is a cross-sectional view of a cylinder plug 3 which includesdouble rows of tumblers 5 and double side-bars 6, wherein the edgesurface of the key (not shown) is also intended to coact with toptumblers 12, 13.

In the case of this lock embodiment, the key is provided with a grooveon each side surface thereof, and the edge of the key blade is providedwith a top code.

FIG. 20 illustrates a cylinder lock-key-combination according to analternative embodiment comprising a lock cylinder 2 and a key 4. Thelock cylinder 2 includes a plug 3 which is provided with a key slot 3a.

As will be seen from FIG. 22, the plug 3 includes a row of key-actuablepin tumblers 5 whose axes lie in a symmetry plane through the plug 3,this plane being parallel with the plane of the key slot 3a and spacedtherefrom. The tumblers 5 are movable in said plane and are rotatableabout their long axes.

Each of the tumblers 5 is provided with a flange 5a between itsrespective ends, these flanges being intended to be received in a groove4f in the side surface 4c of the key. The configuration of the groovewill be described in more detail further on.

The key 4 has an top edge surface 4b which may be provided, optionally,in a standard manner, with a code (not shown) for coaction with furthertumblers (not shown) in the cylinder plug.

The key 4 has a key grip 4a and a side part 4c which is provided withthe aforesaid groove 4f for coaction with the tumbler flanges 5a.

The width of the groove 4f varies and the groove includes a number ofstraight code parts 4e and a number of angled transition parts 4g whosewidths are greater than the widths of the code parts 4e.

As indicated at 4h, the groove widens outwardly in the region of the tipof the key, therewith to ensure positive engagement with the tumblerflanges 5a.

As the key 4 is inserted, the groove 4f will engage with the tumblerflanges 5a, both on the top and the bottom sides thereof. The tumblerswill therefore be forcibly guided by the key to their respective codepositions.

The lengths of respective tumblers 5 correspond to the diameter of theplug 3. Located above and below each tumbler 5, which in this case canbe called the central tumblers, is a tumbler 13 and 14 which arereferred to here as the top and the bottom tumblers respectively. Thetop tumbler 13 and the bottom tumbler 14 are both activated by arespective spring 15 and 16 which have mutually different springstrengths.

The force exerted by the spring 15 is substantially greater than theforce exerted by the spring 16, and the difference between the forcesexerted by the mutually counteracting springs 15, 16 correspondsapproximately to the force of a tumbler spring of a "conventional"cylinder lock.

As will be seen from FIG. 22, the arrangement is such that when astronger spring 15 activates a top tumbler 13 and a weaker spring 16activates a corresponding bottom tumbler 14, the reverse applies tomutually adjacent tumblers, i.e. a weaker spring 16 activates the toptumbler 13, and so on. Accordingly, the resistance exerted by thetumblers on the key as it is inserted into the lock will correspond tothe resistance exerted normally in a cylinder lock.

At the same time, an inventive cylinder lock which includes a centralpin tumbler and top and bottom tumblers which are activated by springsof mutually different strengths affords the advantage of being much moredifficult to force than a lock constructed in accordance with theaforegoing.

The ends of the central pin tumblers are conveniently bevelled orchamfered, as are preferably also the ends of the top and bottomtumblers 13, 14 coacting with the ends of the central tumblers.

The flanges 5a of the central tumblers 5 are received by and guided inthe bores 3d in the plug 3.

In the case of the alternative principal embodiment illustrated in FIGS.23-26, the key 4 includes an engagement member in the form of a rail 4kwhich projects out from the side surface 4c of the key, and the centraltumblers 5 include a receiving member in the form of a waist 5k whoseaxial extension exceeds the width of the rail 4k on the key 4. The rail4k on the key 4 has parts 4k' and intermediate transition parts 4k"corresponding to the relevant code positions.

Thus, as the key is inserted into the lock, the rail 4k engages thewaists 5k of respective central tumblers 5 while moving the tumblers 5to their respective code positions.

The waist 5k of respective tumblers 5 is delimited by conicaltransmission parts 5e, thereby facilitating engagement of the rail 4kwith the central pin tumblers.

As will be seen from FIG. 26, this embodiment includes top tumblers 13and bottom tumblers 14 above and below each of the central tumblers 5.The tumblers are activated by springs 15 and 16, which may have mutuallydifferent strengths.

The rail 4k may be formed on a key of the kind illustrated in FIG. 23 inany one of a number of ways. For instance, the rail may be formed bymechanically cutting the rail in the key material or may have the formof a separate strip which is brought to the desired shape and thenjoined to the main part of the key, for instance welded, soldered orfused thereon. Alternatively, the key may be moulded.

FIGS. 29 and 30 illustrate a further embodiment of the first principalalternative of the invention, in which the lock cylinder 2 is circularand the plug 3 accommodates key-actuable tumblers or latching pins 5whose lengths correspond to the diameter of the plug and which are notactivated by springs. As the key is removed from the lock, the tumblersor latching pins 5 move to their respective latching positions under theinfluence of gravity and/or the code groove position at the tip of thekey. The pin tumblers are provided with a flange 5a for coaction with akey of the kind illustrated in FIG. 20. In order to enable the key toengage the central flange of respective pin tumblers, there is providedon each side of the central flange a shoulder 5b whose diameter isslightly greater than the diameters of the tumbler-accommodating bores3e, 2d in the plug and the lock cylinder respectively. This ensures thatthe front part 4h of the groove 4f in the key 4 will always engage withthe central flange 5a.

It will be understood that the embodiment illustrated in FIG. 29 is ofvery simple design.

FIGS. 31-33 illustrate a further modified key according to the secondprincipal alternative, in which the key blade is provided with a rail.

In this embodiment, the width of the rail 4k varies along the length ofthe key. In this case, the straight parts 4k' are wider than the slopingtransition parts 4k", i.e. the reverse prevails in relation to a groovedkey according to the first principal alternative illustrated in FIGS.17-19 for instance.

As will be seen from the sectional view of FIG. 32, the rail 4k' has agenerally smaller width at the junctions between straight and slopingparts, so that those tumblers which are activated by the rail are movedforcibly, in the absence of any play, in the axial direction of thetumblers, at the same time as the tumblers are free to rotate abouttheir longitudinal axes.

It will be apparent from the aforegoing that the mutually adapted andmutually coacting engaging and receiving members of the tumblers and thelock key ensure that the tumblers are forcibly guided in two oppositeaxial directions to respective code positions as the key is inserted. Atthe same time, the tumblers are able to rotate around their respectiveaxes through one or more turns or parts thereof, although not through apredetermined number of degrees.

Although the invention has been described above with reference tovarious alternative embodiments and applications thereof, it will beunderstood by those skilled in this art that an inventive combinationcan be realized in ways other than those described and illustratedwithout departing from the concept of the invention as defined in thefollowing claims.

I claim:
 1. A cylinder lock-key-combination in which the cylinder lock(1) comprises:a) a cylinder which is housed in a cylinder housing (2);b) a plug (3) which is accommodated in the cylinder housing (2) and hasa key slot (3a), which defines a plane, and a row of pin tumblers (5)whose axes lie in one of the plane of the key slot and in a plane whichis substantially parallel with the plane of the key slot, and in whichthe pin tumblers are operative to move in a pin tumbler plane and rotateabout their axes when activated by the key (4); and which key includesc) side regions and a code which is formed in the side regions of thekey and which functions to coact with the pin tumblers (5) in said rowso that subsequent to inserting the key to its operative position in thekey slot (3a), each pin tumbler will occupy a position which allows theplug (3) to be turned,wherein d) the pin tumblers (5) and the key (4)each have a complementary engaging and receiving member (5a, 4f; 5k, 4k)which cooperate to guide the tumblers forcibly in two mutually oppositeaxial directions to respective code positions as the key is inserted,while permitting the tumblers to rotate freely about their respectiveaxes, each said code position being defined by two opposite planarsurfaces on each said engaging and receiving member, respectively.
 2. Acombination according to claim 1, wherein each tumbler (5) includes anengaging member in the form of a circular flange (5a); and in that aside surface (4c) of the key (4) includes a receiving member in the formof a groove (4f) whose width varies along its length so as toaccommodate the circular flanges (5a).
 3. A combination according toclaim 2, wherein the groove (4f) includes the planar surfaces in theform of straight parts (4e) which extend parallel with the key insertiondirection and which normally define the code positions, and furtherinclude intermediate, angled transition parts (4g) of greater width. 4.A combination according to claim 3, wherein a code position is alsodefined by one or more of the transition parts (4g).
 5. A combinationaccording to claim 1, further comprising a recess (3c) in the plug (3)for accommodating a tumbler-coacting side-bar (6) which is movable in aplane substantially perpendicular to the tumbler plane; a groove (2a) inthe cylinder housing (2) for accommodating the side-bar (6) in itslocking position; and a member (6a) comprising a tongue on the side-bar(6), which, in its release position, coacts with a corresponding member(5b) comprising one of a groove and a waisted portion on respectivetumblers in the row, so that the side-bar is operative to leave thegroove (2a) in the cylinder housing (2) as the plug (3) is rotated,wherein the side-bar (6) is activated by at least one driving pin (7)which coacts with a side surface of the key and which is guided formovement in the plug at right angles to the plane of the key slot (3a)and which urges the side-bar to its locking position as the key iswithdrawn from a fully inserted position with the side-bar (6) in itsrelease position.
 6. A combination according to claim 5, wherein the endof the at least one driving pin (7) distal from the side-bar (6) isreceived in a corresponding depression (4i) in the key (4) when the keyis in its operative position.
 7. A combination according to claim 6,wherein the planar surfaces define straight, normal code positions (4e)on the key groove (4f) which are extended through a distance whichexceeds a radius of respective driving pins (7).
 8. A combinationaccording to claim 6, wherein a depth of the depression (4i) in the key(4) which accommodates the driving pin (7) corresponds to or exceeds thedepth to which the tongue (6b) penetrates into a corresponding waistedportion (5c), of respective tumblers (5).
 9. A combination according toclaim 1, wherein the other side of the key (4) is also provided with agroove for coaction with a further row of tumblers (5) and a furtherside-bar (6) in the plug (3).
 10. A combination according to claim 2, inwhich the tumblers (5) form bottom tumblers for coaction with springactivated top tumblers (13) through the intermediary of one or moreintermediate tumblers, wherein the circular flange (5a) is spaced fromthe end of respective tumblers and has a part (5c; 5e) of smallerdiameter on its top and bottom sides.
 11. A combination according toclaim 2, in which the tumblers (5) function as latching pins, whereinthe circular flange (5a) is spaced from both ends of the tumblers orpins.
 12. A combination according to claim 1, wherein the tumblers (5)include a waisted portion (5k); in that the key (4) includes a rail (4k)which projects out from a side surface (4c) and which includes parts(4k') and intermediate transition parts (4k") corresponding to therelevant code positions; and in that when inserting the key, the rail(4k) engages in the waisted portions (5k) of respective tumblers whilemoving the tumblers to their respective code positions.
 13. Acombination according to claim 12, wherein the waisted portion (5k) ofrespective tumblers (5) is delimited by conical transition parts (5e).14. A combination according to claim 13, wherein there is provided onboth sides of each tumbler at least one further tumbler, including a toptumbler (13) and a bottom tumbler (14), respectively, and at least oneintermediate tumbler (17, 18).
 15. A combination according to claim 14,wherein the top tumbler and the bottom tumbler (13, 14) and theintermediate tumbler (17, 18) are each activated by a spring (15, 16);and in that the springs have mutually different strengths.
 16. Acombination according to claim 15, wherein the difference between thespring strengths of the mutually counteracting springs (15, 16)corresponds approximately to the strength of a normal tumbler spring ofa cylinder lock.
 17. A combination according to claim 16, wherein thesprings (15, 16) of greater or lesser spring strengths alternatelyactivate the top tumblers and the bottom tumblers (13, 14) and theintermediate tumblers (17, 18) in the row, such that adjacent tumblers(5) are urged in different directions and such that essentially an equalnumber of the tumblers (5) are urged in one and the other directionrespectively.
 18. A combination according to claim 14, wherein thetumblers (5) and the top and the bottom tumblers (13, 14) and theintermediate tumblers (17, 18) have bevelled ends.
 19. A combinationaccording to claim 1, wherein the key slot (3a) is positionedasymmetrically in the plug, so that the tumbler axes will lieessentially in the centre plane of the plug.
 20. A combination accordingto claim 1, wherein the tumbler- accommodating bores in the plug (3) andthe bores in the lock cylinder (2) slope in relation to the plug axis atan angle which is smaller than 5° and which is greater than or equal toabout 3°.
 21. A key for a cylinder lock (1) which comprises a cylinderwhich is housed in a cylinder housing (2); a plug (3) which isaccommodated in the cylinder housing (2) and has a key slot (3a), whichdefines a plane, and a row of pin tumblers (5) whose axes lie in one ofthe plane of the key slot and in a plane which is substantially parallelwith the plane of the key slot, and in which the pin tumblers areoperative to move in a pin tumbler plane and rotate about their axeswhen activated by the key (4); said key comprising side regions and acode which is formed in the side regions of the key and which functionsto coact with the pin tumblers (5) in said row so that subsequent toinserting the key to its operative position in the key slot (3a), eachpin tumbler will occupy a position which allows the plug (3) to beturned, wherein each tumbler (5) includes an engaging member in the formof a circular flange (5a); and wherein at least one side surface (4c) ofthe key (4) includes a receiving member in the form of a groove (4f)whose width varies along its length so as to accommodate the circularflanges (5a), and further wherein the groove (4f) has a number ofdefined, planar code position parts (4e) which extend parallel with thekey insertion direction and which correspond to the number of tumblers(5) in the row in the plug (3); in that located between the planar codeposition parts (4e) are transition parts (4g) whose breadth is greaterthan the breadth of the code position parts, the breadths of whichcorrespond to the height or thickness of the circular flanges (5a) andthe breadth of which transition parts (4g) corresponds to the circularflanges (5a).
 22. A method of producing a key from a key blank (4'),said key being for a cylinder lock (1) which comprises a cylinder whichis housed in a cylinder housing (2); a plug (3) which is accommodated inthe cylinder housing (2) and has a key slot (3a), which defines a plane,and a row of pin tumblers (5) whose axes lie in one of the plane of thekey slot and in a plane which is substantially parallel with the planeof the key slot, and in which the pin tumblers are operative to move ina pin tumbler plane and rotate about their axes when activated by thekey (4); said key comprising side regions and a code which is formed inthe side regions of the key and which functions to coact with the pintumblers (5) in said row so that subsequent to inserting the key to itsoperative position in the key slot (3a), each pin tumbler will occupy aposition which allows the plug (3) to be turned, wherein each tumbler(5) includes an engaging member in the form of a circular flange (5a);and wherein at least one side surface (4c) of the key (4) includes areceiving member in the form of a groove (4f) whose width varies alongits length so as to accommodate the circular flanges (5a), said methodcomprising the steps of:passing a cylindrical milling tool (10) having adiameter, thickness and configuration which correspond to the circularflanges (5a) along the key blank (4') in a plane which is parallel withthe plane of the key blank and along a path which includes a pluralityof straight parts (4e) and transition parts (4g) located therebetween;and cutting the groove (4f) in the key blank (4') such that a top side,bottom side and peripheral surface of the milling tool assist in saidcutting, so that the groove (4f) has a greater width in the transitionparts (4g) than in the straight parts (4e) to accommodate the circularflanges (5a) on the pin tumblers when the lock is used.